Geochemical prospecting



L. HORVITZ GEOCHEMICAL PROSPECTING 7 Fil d bee. 9, 1940 ma na. 7, 1943 GEOCHEMICAL rnosrnc'rma Leo Horvitz, Houston, Tex., assignor to. Esme E. Rosaire, Houston, Tex.

Application'December 9, 1 940, Serial No. 369,213

' 3 Qlaims. (G1. 23-230) The present invention is directed to geochemical prospecting, and particularly to that'method of prospecting-according to which soil samples are collected and subjected to a treatment for the recovery therefrom of a gas which is analyzed for the constituents significant of subterranean petroliferous deposits. 1 This application is a continuation in part ofmy, copending application Serial No. 183,960, filed January 8, 1938, now .Patent 2,287,101, issued 4 June 23, 1942, insofar as it is directed to a method for recovering a gas sample from a soil sample by heating the soil sample in a closd space under conditions such that wateris. distilled off of the.

soil sample and subjecting the evolved vapors to a reflux action whereby water is continuously returned to the soil sample. This procedure, insuring, as it does, the continuous presence of water in the soil sample, makes possible th recovcry of a larger sample of gas containing signifi- The pnesentinvention will be better understood sufliciently, which ordinarily is about 100 mm., the valve in line 6 is closed and heat is applied to the bath l. The valve in line 1 is opened and the evolved gas is allowed to expand to a collection chamber (not shown) or is sent directly to an analytical apparatus. The volume of jar 5 is large compared to that of jar 3, or is at least as large as jar 3. This provides a large exposed surface which ordinarily will remain at a temperature not substantially above room temperature, whereby any moisture contained in the evolved gas will collect on the walls of jar 5 and will return to jar 3.

The gas sampl which is collected through line I is usually treated for the removal therefrom of water and CO2 and is then analyzed for si nificant constituents such as hydrocarbons, hy-

drogen, or carbon monoxide.

The apparatus shown in Fig. 2 diifers from that shown in Fig. 1 in that it is provided with an in let for a treating chemical, such as an acid, which by reading the detailed description of the accompanying drawing in; which r Fig. l represents in diagrammatic form a front elevation of one type of apparatus suitable for the practice of the present invention; i Fig; 2 is a similar view of a modified form of apparatus; V

Fig. 3 is a similar view of still another modification. 1

' Referring to Fig. 1 in detail, numeral l desigfrom the soil. In this case the-upper jar 5 is provided with a gas outlet 6 having a valve d'and ahead of this valve having a branch line 9 pro vided with a valve 50. Line 5, as in the case of Fig. 1, is connected with a suitable source of vacua ing downwardly therein is a tube It.

.isof sufiicient length to extend down into the n'ates a'water or oil bath under which is placed a conventional burner 2. Arranged in the heating bath is a jar 3 in which is placed the soil sample 4. The mouth of the jar has a ground surface adapted to mate Witha similar ground surface .of a jar 5 arranged over jar 3 in inverted position. Jar-5 has an outlet 6"for gas which it In thepractice of the invention the soil sampie is placed in the jar 3, and in .5 is'arranged in the position shown. The valve in line I is closed, the valve in line 6 is opened and suction applied, Gas given off at thisstage is discarded :rcm th system. When the pressure is reduced um, and line 9 is connected to a gas collecting chamber or the gas analytical apparatus.

Fused into the top of chamber 5 and extend- This tube jar 3 so that treating chemicals can be dropped directly into the soil.v It should be noted als that in this embodiment the shape of vessel 5 is changed so as to provide more wall surface.

In the embodiment shown in Fig. 3, the Jar dis replaced by a conventional reflux condenser having an inner tube [3 provided with a jacket I l which has a water. inlet l5 and a water outlet it. At the upper end. of tube l 3 is the gas outletB which is the same as that shown in Fig. 2. It is provided with a branch line 9, as in Fig. 2. Arranged concentrically in the tube is is an inner tube ll provided with, a valve i8. tube, as in the case of Fig. 2, is oi suflicientlength tmextend down in vessel 3 so as to permit the addition of chemicals to the soil in this vessel.

It will be apparent that changes may be made in the apparatus shown without departing from the scope of the present invention. The essentiaffeature isthat-means' is provided above the sample chamber containing the soil sample 'i'or condensing water out of evolved gas so that this water maybe returned to the soil sample.

The nature and objects'of the'present' invent on having been thus described and illustrated, what is claimed as new and useful and is desired to be secured by Letters Patent is:

1. A method for treating a soil sample containing entrained or adsorbed normally gaseous hydrocarbons in conjunction with water for therecovery therefrom of a hydrocarbon-containing gas sample for analysis Which comprises confining the soil sample in a closed system, subjecting the sample to evacuation and heating whereby entrainedgases and moisture contained therein are evolved, condensing a substantial portion of the moisture contained in the evolved gas to thereby leave a residual gas for analysis which is drawn off from said system, and returning the condensate to the sample.

2. A method for treating a soil sample containing entrained or adsorbed normally gaseous hydrocarbons in conjunction with water for the recovery therefrom of a hydrocarbon containing gas sample for analysis which comprises confin ing the soil sample in aclosed system, subject-- ing thesample to evacuation and heating whereby entrained gases and moisture contained therein are evolved, condensing asubstantial portion of the moisture contained in the evolved gases subjecting the residual evolved gas to a treat- -ment for the removal therefrom of carbon dioxide and any remainingwater, thereby placing the residual gas in a condition suitable for thereof for hydrocarbons. v

3. A method for treating a soil sample containing entrained and adsorbed normally-gas'e ous hydrocarbons in conjunction with .water for' the recovery therefrom of a hydrocarbon containing gas sample for analysis which comprises 7 confining the sampleinaclosed system. subjectf ing the sample to a pressure substantially below atmospheric for a period of time sufiicient to remove interstitial gas from the sample, discarding said gas from the system, then subjecting the sample to heat while maintaining subatmospheric LEO nonvrrz.

and returning the .condensate to the sample and analysis 

